Safety door actuator



Aug. 9, 1966V H. L. MlLLa SAFETY DOOR ACTUATOR United States Patent O Michigan Filed Dec. 3, 1964, Ser. No. 415,619

11 Claims. (Cl. 49-26) This invention relates to a garage door operating mechanism and more particularly to a mechanism which has a safety release feature in the event the door hits an obstruction.

In my copending application Serial No. 212,587, led July 26, 1962, now P-atent No. 3,193,274, there is disclosed and claimed a safety release mechanism which is independent of the electrical circuit and operates to prevent damage in the event that the garage door encounters an obstruction in closing. Basically, the safety door actuator disclosed in my prior application includes a power shuttle that is movable along a lineal track, a second shuttle which is associated with an actuator arm of a garage door, spring biased means on the power shuttle forming a re-entrant recess and anchor means on the second shuttle releaseably receivable in the re-entry recess of the power shuttle so that the shuttles may be releaseably engaged for normal operation of the door.

It is an object of the present invention to provide an improved safety release mechanism of the type disclosed and claimed in my prior application.

It is a further object of the invention to provide such a safety release mechanism which is more easily adjusta'ble, less expensive and can be easily added to an existing door operating mechanism.

Other objects and features of the invention relating to details of construction and operation will be apparent in the following description and claims.

Drawings accompanying the disclosure and the various viewsthereof may be briey described as:

FIGURE 1, a side view of a door operating assembly.

VFIGURE 2, a part-sectional plan view on an enlarged scale of a portion of the assembly shown in FIGURE l.

FIGURE 3, a fragmentary sectional view on an enlarged scale taken along the line 3-3 in FIGURE l.

Referring to the drawings:

The. mechanism consists primarily of the housing 20, a driving motor 22, a guide -track 24 and a drive chain 26. The header 30 of a garage door is shown adjacent which is mounted in suitable vertical and horizontal tracks; (not shown) 'a vertical-lift garage door 32 of standard construction. Suitable and standard counterbalance mechanisms can be used. On the housing 20 1s a bracket 34 which serves as a support to be bolted or suspended within the garage in horizontal spaced relation to the header 30. Guide track 24 is preferably an angle iron of inverted T-shape bolted to the forward end of the housing 20 at 36 and suspended at the outer end 'by an angle bracket 38 on header 30 and a shart insert 40 joined to the angle bracket at 42 and to the angle mount 24 at 44.

On the short insert 40 is mounted an idle sprocket 46 to support one end of the chain 26. A drive sprocket 48 on the housing 20 serves to power the chain. A center support bracket 50 for the guide iron 24 is provided. The motor 22 drives the pulley 52 which, in turn, through a belt 54, drives a large pulley 56 which is connected to the drive sprocket 48.

Slidably mounted on the guide track 24 is a power shuttle block 60 made of two sheet metal members 61 shaped as shown in FIGURE 3 to have suitable engagement with the horizontal flanges of the track 24. A pillar block 62 is securely fastened to the side of shuttle 3,264,785 Patented August 9, 1966 block 60, this block being apertured to receive a pin on one end of the chain 26 which is adjustably anchored to the block by nuts 64 and 66. Pillar block 62 is located at one end of the shuttle block and at the other end is a second pillar block 68 also apertured to receive the other end of chain 26 which is pinned in position by a small cross pin 70. A

Depending from the bottom surface of shuttle block 60 .as a part of the side members 61 are two parallel flanges 72 and 74 positioned in spaced relation. The flanges 72, 74 have, respectively, circular detent openings 76, 78 therein which extend inwardly toward one another and face one another. The anges 72, 74 are spaced from one another and held in position by spacers 80 through which bolts 82 extend and nuts 84 are threaded on the bolts 82.

A second shuttle block made of two sheet metal members is also provided on the track 24 and includes downwardly extending flanges 92, 94. The two shuttle lblocks 60, 90 are preferably of identical sheet metal construction in order that they can be used interchangeably in production and can be modied so that the garage door operator can be converted to include the safety feature even after installation, as presently described. Spacers 96 hold the flanges 92, 94 in spaced relation. A pair of plates 98, 100 are fastened on the flanges 92, 94 by the bolts 102 and nuts 104 that extend through the spacers 96. Detents are provided on the portion of the plates 98, 100 that overlie detent recesses 76, 78 and comprise Iballs 106, 108 that are yieldingly urged inwardly by springs 114 within tubes 110, 112 welded on the plates 98, 100. The compression forces of the springs 114 are adjusted by threaded members 118 and 120 which are threaded into the tubes 110, 112. Transverse pins 122, 124 on the threaded members 118, 120 facilitate the manual adjustment of the spring forces. The mem'bers 118, are preferably made of a plastic material such as Delrin which locks in position and prevents inadvertent change in the adjustment. The inner ends of tubes 110, 112 are restricted sufficiently to retain the balls in the tubes. In practice, the L-shaped door .actuator 126 is pivotally anchored at the door on bracket 128. This actuator 126, which is adjustable in length due to an overlap and bolts 132, is pivotally anchored at its upper end on bolt 102 (FIGURE 2). The upper end is notched at 134 and a spring biased sheet metal slide 136 mounted on bracket 128 locks the actuator bar on bolt 102. The slide 136 is retractable by a chain 138 to permit release when desired. When the door encounters an obstacle, in being lowered, the power shuttle 60 continues to move but the balls 106, 108 move out of the detent recesses 76, 78 releasing second shuttle 90 and, in turn, the door from the power. The second shuttle 90 can be readily re-engaged with the power shuttle 60 by moving the second shuttle 90 toward the power shuttle or by reversing the power shuttle 60 and holding the door momentarily to cause the balls 106, 108 to engage the recesses 76, 78.

The structure embodying the invention can be readily adjusted by rotation of the members 11S, 120 so that the force for disengagement of the door can be controlled. In addition, since the shuttle members 60, 90 are of substantially identical constructions, the safety device can 'be added after a basic door operator has been applied by merely adding the additional shuttle 90 and moving the actuator arm 126 from engagement with a pin 96 to the second shuttle 90.

It will thus be seen that there is disclosed a disengageable shuttle arrangement readily constructed from four identical stampings which form the parts 61 and 91. In addition, the assembly adapts itself to the optional use of .a direct drive .from power shuttle to door or the addition either in original Vequipment or later as optional accessory ,of the disengagement shuttle. ture has a ready adjustment adapted for a stable setting over prolonged operation periods.

I claim:

1. In a garage door operating mechanism wherein a lineal power shuttle operates an actuator arm connected to a vertical lift door to raise and' lower the: door and wherein there `is utilized a safety release combination including a guide track, av power shuttle on said track, and a second shuttle on saidrtrack releaseably associated with an actuator arm of a garage door, that improvement in a shuttle construction which comprises n (a) a set of four substantiallyidentical plates each shaped to have a sliding engagement with a track,

(b) means joining said plates in two opposed pairs on said track to form longitudinally aligned shuttles,

(c) one of said shuttlesy having opposed recesses on an axis transverse of said track, and

(d) means mounted on the second of said shuttles'positioned to overlie a portion of said one shuttle containing said recesses to resiliently engage said recesses,

whereby said shuttles are `normally engaged for tandem voperation and separable upon a predeterminedresistance to door movement.

2., A device as defined in claim 1 in which the means mounted on thel second of said shuttles comprises a detent cylinder, a detent projecting therefrom to vengage a said recess, resilient means behind said detent, and anadjust-l ment plug in said cylinder, adjacent said resilient means,y movable in said cylinder in a metal to plastic engagement for frictionaladjustment therein.

3. The combinationfset forth in claim 2 wherein said springloaded detent members comprise a ball, a spring yieldingly urging said ball toward said-recess, and a threaded member axially adjustable and engaging said spring to adjust the spring tension on said ball'andtfhereby adjust the release force on said power shuttle. f

4.'The combination set forth in claim 2 wherein said track has a T-shaped transverse cross section.

Also the struc- 5. The combination set forth inclaim 2 wherein eachy Y said shuttle member is madex of sheet metal and comprises vsubstantially identical members.

6. The combination set forth in claim 2 wherein said shuttle members are of substantially identical construction.v

8. A device as defined ,in claim 7 v'in which thel detent:

means each comprise a cylinder, a ball at one end thereof to engage a recess; a compressible spring behind each ball, f and ak plastic screw plug .in isaid cylinder engaging saidy spring andV frictionally movable .in said cylinder axially to control the force of said-spring on said ball.

9. Thecombination set forth in claiml 7 'wherein said threaded member comprises plastic material.-

10.'In a garage ydoorY operating mechanisml wherein la lineal'power shuttle operates'an actuator arm connected to a verticalflift doortoraise andlower'the door, a safetyv release combination `comprising (a) a guide track, (b)y a power shuttle; on said track,

actuator arm of a garage door,

(d)` *one ofy said shuttleshavinga transversely extending recess therein,y`

(e) the other vof saidshu-ttles having a spring loaded detent member extending transversely andadapted to enter and yieldingly releaseably engageI theY recess on the first mentioned shuttle..

11. In a garage door. operating mechanism wherein a linealpower shuttle operates an actuator arm connected to a verticaldft door to raise andlowerthe door, a safety release combination comprising (a) aguidetrack,l (b) -a power-shuttle on said'track; (c) a secondtshuttle on said vtrack associatedwith an actuator-ann of la' garage door,

y (d) said power shuttle having diametrically opposed inwardly extending dentent recesses fthereon,

shuttlefor normaloperation of said door.

References; Cited byfthe vExaminer Y UNITED STATES lPATENTS`v 3,043,247 7/1962 "McKeegetfalf 104-128 3,091,191 5/1963 Fur 104-172 3,193,274 7/1965 Millert v.. 26S-59 Y v3,207,500 9/1965 KOOy= c 268%59 f HARRISON R.V MOSELEYQPrim'ary Examiner. I. K. BELL; Assistent Examiner. i

(c)r` a `second shuttle ,on saidtrack associated with an: 

1. IN A GARAGE DOOR OPERATING MECHANISM WHEREIN A LINEAL POWER SHUTTLE OPERATES AN ACTUATOR ARM CONNECTED TO A VERTICAL LIFT DOOR TO RAISE AND LOWER THE DOOR AND WHEREIN THERE IS UTILIZED A SAFETY RELEASE COMBINATION INCLUDING A GUIDE TRACK, A POWER SHUTTLE ON SAID TRACK, AND A SECOND SHUTTLE ON SAID TRACK RELEASABLY ASSOCIATED WITH AN ACTATOR ARM OF A GARAGE DOOR, THE IMPROVEMENT IN A SHUTTLE CONSTRUCTION WHICH COMPRISES (A) A SET OF FOUR SUBSTANTIALLY IDENTICAL PLATES EACH SHAPED TO HAVE A SLIDING ENGAGEMENT WITH A TRACK, (B) MEANS JOINING SAID PLATES IN TWO OPPOSED PAIRS ON SAID TRACK TO FORM LONGITUDINALLY ALIGNED SHUTTLES, (C) ONE OF SAID SHUTTLES HAVING OPPOSED RECESSES ON AN AXIS TRANSVERSE OF SAID TRACK, AND (D) MEANS MOUNTED ON THE SECOND OF SAID SHUTTLES POSITIONED TO OVERLIE A PORTION OF SAID SHUTTLE CONTAINING SAID RECESSES TO RESILIENTLY ENGAGE SAID RECESSES, WHEREBY SAID SHUTTLELS ARE NORMALLY ENGAGED FOR TANDEM OPERATION AND SEPARABLE UPON A PREDETERMINED RESISTANCE TO DOOR MOVEMENT. 